There are method for detecting an electrical fault in an electrical network of a motor vehicle. Particularly, in modern motor vehicles having a hybrid drive train, that is, having at least one internal combustion engine and at least one electrical machine mechanically connectable to the internal combustion engine, it is frequently of interest to detect malfunctions or faults in the electrical network, which includes the electrical machine, so as to protect components of the electrical network, in particular the pulse-controlled inverter. Such a network normally also has at least one rechargeable battery and at least one d.c. voltage converter, the battery being used as the voltage source for the electrical machine associated with the pulse-controlled inverter or as an energy store in the generator operating mode of the electrical machine. In the case of a fault or a malfunction, different options for operating the electrical network are known such that for example an emergency operating mode is started or the system shuts down when a fault is detected. In this connection, the current of an intermediate circuit of the electrical network associated with the pulse-controlled inverter is frequently detected with the aid of an intermediate circuit current sensor. Faults in the electrical network, in particular a fault in the intermediate circuit current sensor, may result in false information regarding the operability of the electrical network.